多自由度波浪能装置参数激励运动研究  

Investigation on parametrically excited motions of multiple degrees of freedom wave energy converter

作　　者：王冬姣[1] 陈昌润 刘鲲 邱守强[1] WANG Dong-jiao;CHEN Chang-run;LIU Kun;QIU Shou-qiang(School of Civil Engineering and Transportation,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]华南理工大学土木与交通学院,广东广州510640

出　　处：《浙江大学学报（工学版）》2022年第12期2496-2506,共11页Journal of Zhejiang University：Engineering Science

基　　金：国家重点研发计划项目(2018YFB1501904);国家自然科学基金资助项目(51809096);广东省自然科学基金资助项目(2021A1515012059)。

摘　　要：为了研究多自由度波浪能装置的参数激励运动及其对波能俘获能力的影响,利用势流理论建立多自由度轴对称型波浪能装置的频域和时域仿真模型,将垂向动力输出(PTO)机构安装在PTO管内,使浮体在波浪作用下沿管滑动.纵、横摇铰接轴分别连接PTO机构,PTO阻尼力矩与纵、横摇角速度成正比.设垂向PTO阻尼力与浮体沿管滑动速度成正比,为了评估参数激励运动,仅在时域模型中将垂向PTO阻尼力分解到垂向和水平方向时保留非线性项.结果表明,垂向PTO阻尼力是装置产生参数激励运动的主要原因.产生参数激励运动时,垂向PTO俘获的波浪能降低,参数激励运动的周期范围随波高、垂向PTO阻尼系数的增大而变宽.随浪工况,垂向和纵摇PTO均连接PTO阻尼时,若纵摇PTO阻尼力矩系数较小,则参数纵摇和参数横摇同时发生;反之,若纵摇阻尼力矩系数较大,参数纵摇受抑制,但会产生大幅值参数横摇;若要完全抑制装置的参数共振,纵摇和横摇PTO均须设置适当大小的PTO阻尼.In order to explore parametrically excitation motions of wave energy converter and its influence on wave energy capture capability,both the frequency domain and time domain simulation models of a multiple degrees of freedom wave energy converter with a vertical axis of symmetry were established based on the potential flow theory.A vertical power take-off(PTO)mechanism was installed inside PTO pipe,allowing a floating buoy to slide along the pipe under wave action.The pitching and rolling articulated shafts are connected with the PTO mechanism respectively,and the corresponding PTO damping torque is proportional to the angular speed of pitching and rolling.Setting damping force of vertical PTO is proportional to the sliding speed of the floating buoy along the PTO pipe,in order to assess the occurrence of large amplitude parametric resonance in the time domain model,when the vertical PTO force is decomposed into vertical and horizontal directions,the nonlinear term is retained,while the nonlinear term was ignored in the frequency domain model.Results show that the parametrically excitation motions are mainly caused by vertical PTO damping force.The wave energy captured by the vertical PTO will be reduced due to occurrence of parametrically excited motions,and a period range of the parametrically excitation motions will become widen with the increase of wave height and vertical PTO damping coefficient.In the following sea waves,both the vertical and pitch PTO were connected with PTO damping,if the damping torque coefficient of pitch PTO is small,then the parametric pitching and rolling occur together.On the contrary,if the pitch PTO damping is large the parametric pitching can be suppressed, but large amplitude parametric rolling will occur. Therefore, in order to completely suppress the parametric resonance of the converter, both pitch and roll PTO mechanisms need to set a certain mount of PTO damping.

关 键 词：多自由度 波浪能装置 参数横摇 参数纵摇 参数激励 数值模拟 

分 类 号：P743.2[天文地球—海洋科学]